Connection method for flexible board and a flexible board connector

ABSTRACT

The present invention suggests a flexible board connector having a frame element, which comprises an insertion opening, and a cover element. The frame element is provided and intended for being mounted to a circuit board. The insertion opening is provided and adapted to accept a flexible board, which has at least one conductive contact on a first side thereof. The cover element has at least an opened position and a closed position. When the cover element is in the closed position, the cover element is adapted for exerting a pressure against a second surface of the flexible board, when the flexible board is inserted through the insertion opening into the frame element of the flexible board connector.

The present invention in general relates to a method for electricallyconnecting one or more contacts of a flexible board to one or morecontacts of a circuit board, a flexible board connector and a connectorstructure.

In recent years, electronic devices of portable telephones, videocameras and the like have been promoted reducing their size and weightwhile internally included many built-in electronic components. Many ofthe electronic components have leads and terminals electricallyconnected with solder to component mounting lands arranged on a circuitboard. In portable telephones, of which the size reduction has beenpromoted, even comparatively large components such as LCD modules andkeypads are arranged on a circuit board, and a plurality of such circuitboards are normally employed. In order to electrically connect theplurality of circuit boards with one another, many flexible boards areemployed. Moreover, flexible boards are employed to electrically connectother parts of camera modules and so on to the circuit board.

However, known flexible board connectors suffer significantdisadvantages. The present invention provides a new connection methodand a flexible board connector making use of the method.

According to a first exemplary aspect of the present invention, aflexible board connector is provided, which comprises a frame element,which has an insertion opening, and a cover element. The frame elementis provided and intended for being mounted to a circuit board. Theinsertion opening is provided and adapted to accept a flexible board,which has at least one conductive contact on a first side thereof. Thecover element has at least an opened position and a closed position.When the cover element is in the closed position, the cover element isadapted for exerting a pressure against a second surface of the flexibleboard, when the flexible board is inserted through the insertion openinginto the frame element of the flexible board connector.

According to an exemplary embodiment of the present invention, the atleast one conductive contact on the flexible board is arranged againstat least one conductive contact on the circuit board, when the coverelement is arranged in closed position. In particular, the at least oneconductive contact on the flexible board is arranged in touching contactwith the at least one conductive contact on the circuit board, and moreparticularly, at least one conductive contact on the flexible board ispressed against at least one conductive contact on the circuit board.

According to an exemplary embodiment of the present invention, in theclosed position, the cover element is adapted for detachably retainingthe flexible board in the flexible board connector by exerting thepressure onto the second surface of the flexible board such that the atleast one conductive contact of the flexible board and the at least oneconductive contact of the circuit board facing each other are pressedagainst each other, which causes the conductive contacts to get intoelectric connectivity with each other and to effect a retention forceagainst a pulling actuation on the flexible board, which might causeremoving the flexible board from the flexible board connector.

According to an exemplary embodiment of the present invention, thecircuit board has at least one conductive contact or a plurality ofconductive contacts. The frame element is arranged on the circuit boardto house the conductive contacts thereon. The one or more conductivecontacts of the circuit board are firmly arranged thereon.

According to an exemplary embodiment of the present invention, theflexible board has at least one conductive contact or a plurality ofconductive contacts. The one or more conductive contacts of the flexibleboard are firmly arranged thereon.

According to an exemplary embodiment of the present invention, the oneor more conductive contacts of the flexible board are arranged thereonin a predefined arrangement, which substantially conforms to anarrangement of the one or more conductive contacts of the circuit board.In particular, the one or more conductive contacts of the flexible boardand the one or more conductive contacts of the circuit board arerespectively arranged in patterns substantially coinciding witch eachother.

According to an exemplary embodiment of the present invention, the oneor more conductive contacts of said circuit board and the one or moreconductive contacts of said flexible board have substantially congruentor coincident surfaces. In particular, the congruent or coincidentsurfaces of the respective conductive contacts facing each other, whenthe flexible board is inserted into the flexible board connector, form asubstantially common 2-dimensional extended contact surface, withinwhich the respective facing conductive contacts of the circuit board andthe flexible board are in electric contact with each other. Moreparticularly, the 2-dimensional electric contact surface ensures atleast a low or substantially negligible low contact resistance betweenthe conductive contacts in electrical contact with each other.

According to an exemplary embodiment of the present invention, thepressure is caused by a force exerted onto the second surface of theflexible board, which force has at least a normal force componentrelative to the second surface.

According to an exemplary embodiment of the present invention, thesecond surface is opposite to the first surface at which the one or moreconductive contacts are arranged.

According to an exemplary embodiment of the present invention, the coverelement is pivotably attached to the frame element. The cover element ispivotable into the closed position, in which the flexible board isretained in the flexible board connector.

According to an exemplary embodiment of the present invention, theflexible board connector further comprises a resilient element. Upondeformation of the resilient element the pressure is exerted onto thesecond surface of the flexible board.

According to an exemplary embodiment of the present invention, theflexible board connector further comprises a bead element. The beadelement is provided to accept a pressure exerted by a resilient elementand the bead element is further provided to exert a substantiallyuniformed pressure onto the second surface of the flexible board uponexperiencing the pressure exerted by the resilient element.

According to an exemplary embodiment of the present invention, the coverelement has at least a deformable portion. When deformed the deformableportion causes a restoring force effecting the pressure exerted onto theflexible board.

According to an exemplary embodiment of the present invention, the coverelement has a portion being substantially U-shaped and having at leastone deformable leg. When deformed the portion causes a restoring forceeffecting the pressure exerted onto the flexible board.

According to an exemplary embodiment of the present invention, theflexible board connector further comprises a locking element. Thelocking element is adapted for releasably locking the cover element inclosed position, when the locking element is in engagement with thecover element, in particular when the locking element is in mechanicalengagement with the cover element.

According to an exemplary embodiment of the present invention, theflexible board connector further comprises one or more fixing elements.The fixing elements are provided for being firmly mounted to the circuitboard and mechanically engaging the frame element such that the frame isfirmly mounted to the circuit board.

According to an exemplary embodiment of the present invention, the coverelement substantially flushes with the frame element when in closedposition.

According to a second exemplary aspect of the present invention, anelectronic device is provided, which comprises at least one circuitboard with a flexible board connector, which is adapted to accept aflexible board. The circuit board has at least one conductive contact.The flexible board has at least one conductive contact arranged on afirst side thereof. The flexible board connector includes a frameelement, which has an insertion opening, and a cover element. The frameelement is provided and intended for being mounted to a circuit board.The insertion opening is provided and adapted to accept a flexibleboard. The cover element has at least an opened position and a closedposition. When the cover element is in the closed position, the coverelement is adapted for exerting a pressure against a second surface ofthe flexible board, when the flexible board is inserted through theinsertion opening into the frame element of the flexible boardconnector.

According to a third exemplary aspect of the present invention, a methodis provided, which comprises providing a frame element and a coverelement of a flexible board connector. The frame element is mounted to acircuit board and has an insertion opening. The insertion opening isadapted for accepting a flexible board. The flexible board has at leastone conductive contact on a first side of the flexible board. The coverelement is cooperative with the frame element and has at least an openand closed position. The flexible board is inserted into the frameelement and the cover element is arranged with the frame element in theclosed position such that a pressure is exerted against a second side ofthe flexible board.

According to an exemplary embodiment of the present invention, the atleast one conductive contact on the flexible board is arranged againstat least one conductive contact on the circuit board, when the coverelement is arranged in closed position.

According to an exemplary embodiment of the present invention, the frameelement is arranged on the circuit board such that one or moreconductive contacts of the circuit board are housed by the frameelement. The one or more conductive contacts of the circuit board arethinly arranged thereon. The one or more conductive contact of theflexible board are provided in an arrangement confirming to anarrangement of the at least one conductive contact of the circuit board.The one or more conductive contacts of the flexible board are firmlyarranged thereon.

According to an exemplary embodiment of the present invention, thepressure is caused by exerting a force onto the flexible board. Inparticular, the exerted force has at least a normal force componentrelative to the second surface.

According to an exemplary embodiment of the present invention, whereinthe cover element is pivotably attached to the frame element. The coverelement is pivoted into the closed position, in which the flexible boardis retained in the flexible board connector.

According to an exemplary embodiment of the present invention, aresilient element is provided and the resilient element is deformed tocause the pressure exerted onto the flexible board.

According to an exemplary embodiment of the present invention, a beadelement is provided, which is adapted to accept the exerted pressure;and the bead element is used to exert a uniformed pressure onto theflexible board.

According to an exemplary embodiment of the present invention, the coverelement has at least a deformable portion. The at least one deformableportion is deformed such that a restoring force is caused, which effectsthe pressure exerted onto the flexible board.

According to an exemplary embodiment of the present invention, whereinthe cover element has a portion being substantially U-shaped and atleast one deformable leg. The at least one deformable leg is deformedsuch that a restoring force is caused, which effects the pressureexerted onto the flexible board.

According to an exemplary embodiment of the present invention, a lockingelement is provided. The locking element is engaged with the coverelement in the closed position and the cover element is releasablylocked in the closed position.

According to an exemplary embodiment of the present invention, one ormore fixing elements are provided, which are firmly mounted to thecircuit board and mechanically engage with the frame element.

These and other additional objects and features of the present inventionwill become readily apparent when the same are set forth in greaterdetail in the accompanying detailed description of the embodiments withreference being made to the drawings in which like reference numeralsrepresent like or similar parts throughout and in which:

FIG. 1 a is a schematic exploded view showing principle components of aflexible board connector 1 according to an exemplary embodiment of thepresent invention;

FIG. 1 b is a further schematic view showing the principle components ofFIG. 1 in cooperation with each other according to an exemplaryembodiment of the present invention;

FIG. 1 c shows different exemplary shapes of conductive contactsaccording to exemplary embodiments of the present invention;

FIG. 2 is a schematic plan view of the flexible board connector mountedon the circuit board for detachably retaining the flexible boardaccording to an exemplary embodiment of the present invention;

FIG. 3 shows plan and side view of the flexible board connector mountedon the circuit board for detachable retaining the flexible boardaccording to an embodiment of the present invention;

FIG. 4 is a perspective view of a flexible board connector according toan exemplary embodiment of the present invention;

FIG. 5 a is a schematic view of the flexible board connector of FIG. 4illustrating the cooperation of the components of the flexible boardconnector;

FIG. 5 b is another schematic view of the flexible board connector ofFIG. 4 illustrating the cooperation of the components of the flexibleboard connector;

FIG. 6 is a perspective view of another flexible board connectoraccording to an exemplary embodiment of the present invention;

FIG. 7 a is a schematic view of the flexible board connector of FIG. 6illustrating the cooperation of the components of the flexible boardconnector; and

FIG. 7 b is another schematic view of the flexible board connector ofFIG. 6 illustrating the cooperation of the components of the flexibleboard connector.

FIG. 8 is a schematic plan view of the flexible board connector mountedon the circuit board for detachably retaining the flexible boardaccording to an exemplary embodiment of the present invention.

The present invention will be described in detail below on the basis ofexemplary embodiments shown in the drawings.

The following embodiments are described in sufficient detail to enablethose skilled in the art to practice the invention, and it is to beunderstood that the embodiments may be combined, or that otherembodiments may be utilized and that structural, logical, and electricalchanges may be made without departing from the spirit and scope of thepresent invention. It should be noted that references to “an”, “one”, or“various” embodiments in this document are not necessarily to the sameembodiment, and such references contemplate more than one embodiment.

FIG. 1 a shows an exploded view of principle components of a flexibleboard connector 1 according to an exemplary embodiment of the presentinvention. The flexible board connector 1 is provided for detachableretaining or fixing a flexible board 30 to a circuit board 40 andelectrically connects the wiring of the flexible board 30 to the circuitof the circuit board 40.

The circuit board 40 has a plurality of conductive contacts 45 forelectrically connecting the circuit of the circuit board 40 to thewiring of the flexible board 30. The conductive contacts 45 of thecircuit board 40 are embodied as conductive pads each having asubstantially planar conductive surface.

The flexible board 30 has a plurality of conductive contacts 35 forelectrically connecting the wiring of the flexible board 30 to thecircuit of the circuit board 40. The conductive contacts 35 of theflexible board 30 are embodied as conductive pads each having asubstantially planar conductive surface.

The flexible board connector 1 is designed to bring the conductivecontacts 45 and the conductive contact 35 into an arrangement, in whichthe conductive contacts 45 of the circuit board 40 and the conductivecontacts 35 of the flexible board 30 are facing each other and in directcontact such that an electrical connection between them is enabled.

The conductive contacts 35 and 45 may be substantially designed asrectangular solids, which project at a predefined height from thesurface of the flexible and circuit boards, respectively. The inventionshould not be understood as being limited to rectangular solids;alternatively shaped conductive contacts 35 and 45 may also be used.However, in order to ensure a reliable electric connection between thecontacts 35 and 45 facing each other, the facing surfaces should besubstantially planar such that a direct planar electrical contact isformed.

In order to ensure reliable electrical contact a force or pressure(indicated with reference numeral 61 in FIG. 1 b) is applied on the backsurface of the flexible board 30, which presses the facing conductivesurfaces of the conductive contacts 45 of the circuit board 40 and theconductive contacts 35 of the flexible board 30 against each other. Theforce 61 should be a normal force 61 (i.e. normal in relation to theconductive surface of the contacts 35 and 45) or should be a force 61having a normal component. Such a normal force may be exerted by aresilient, spring or elastic element 60, which upon deformation exerts anormal force onto at least the region of the flexible board 30, withinwhich the conductive contacts 35 are arranged. A cover element 70 may beused for exerting the deforming force 61 onto the resilient element 60.

The force 61 applied to the resilient element 60 may deform theresilient element starting at a height a, when there is not applied aforce thereto, to have a deformed height a′ at a given magnitude offorce.

The normal force may be exerted onto the back surface of the flexibleboard 30, which is the opposite surface to the surface, at which theconductive contacts are arranged.

In order to ensure a substantially uniform pressure exerted onto theconductive contact 35 of the flexible board 30, a bead element 50 may bearranged between the resilient element 60 and flexible board 30according to an exemplary embodiment of the present invention.

Although the exemplary embodiment illustrates, surfaces of theconductive contact 35 and 45, which are substantially parallel to thesurface of the flexible 30 and circuit boards 40, respectively, theinvention should not be understood as being limited thereto. Theconductive contacts may also have side surfaces substantiallyperpendicular to the base surface defined by the corresponding board;rounded surfaces (cf. FIG. 1 c, exemplary embodiment (a)); side surfacesinclining at predetermined angle(s) in relation to the base surface andtitled in direction to each other (cf. FIG. 1 c, exemplary embodiment(b)); tapered shapes in side view (cf. FIG. 1 c, exemplary embodiment(c)); or any combination thereof such as exemplary embodiment (d) ofFIG. 1 c, where the conductive contacts 35 have a substantiallyrectangular shape in side view and the conductive contacts 45 have asubstantially tapered shape in side view. According to another exemplaryembodiment of the present invention, the surfaces should not beunderstood as being limited to planar surfaces. The surfaces of thefacing conductive contacts (i.e. the respective contacts of the circuitboard and the flexible board facing each other, when the flexible board30 is properly inserted into the flexible board connector 1) may beshaped congruently or coincidently. For instance, one of the surfaces ofthe respective facing conductive contacts may have convex orsubstantially spherical shape, whereas the other one may have acongruent concave or inverse spherical shape. More generally, therespective facing conductive contacts may have coincident or congruentshaped surfaces, which ensure a common 2-dimensional extended contactsurface of the facing conductive contacts with each other.

A force normal to the surfaces of the conductive contacts 35 and 45facing each other exert a pressure, which should be substantiallyuniform such that reliable electric connectivity between the conductivecontacts 35 of the flexible board 30 and the conductive contacts 45 ofthe circuit board is ensured.

In common to all exemplary embodiment described above, the conductivecontacts of the circuit board and the flexible board should have one ormore (predefined) heights such that the conductive surfaces of thecontacts are spaced at defined heights from the surfaces of the circuitand flexible boards. More generally, the conductive contacts of thecontacts should project over the surfaces of the respective board. Inparticular, solder masks around the conductive contacts may be avoided.The projecting contacts guarantee that the respective facing conductivecontacts of the circuit board and flexible board can get into direct and2-dimensional contact without interference by for instance any adjoiningelements, which may hinder the getting into contact of the facingconductive contacts of the circuit board and flexible board.

FIG. 2 illustrates a schematic plan view of the flexible board connectormounted on the circuit board according to an exemplary embodiment of thepresent invention. The flexible board connector 1 is provided fordetachably retaining the flexible board and for ensuring reliableelectric connectivity between the conductive contacts of the circuitboard 40 and the detachably retained flexible board 30, respectively. Asschematically indicated in FIG. 2, the conductive contacts 45 areconnected to individual wiring 46 of the circuit of the circuit board40. The conductive contacts 45 may be formed by an etching or corrodingprocess of a conductive surface layer of the circuit board 40. Theconductive contacts 45 may also be soldered to the circuit of thecircuit board 40, fixed by conductive adhesive substance thereto, or maybe firmly attached in any other suitable manner to the circuit of thecircuit board 40.

The conductive contacts 35 are connected to individual wiring 36 of theflexible board 30. Further, the conductive contacts 35 may be formed byprinting conductive substance onto the flexible board 30. The conductivecontacts 35 may also be soldered to the wiring of the flexible board 30,may be fixed by conductive adhesive substance thereto, or may be firmlyattached in any other suitable manner to the wiring of the flexibleboard 30. The conductive contacts 35 may also be formed by an etching orcorroding process of a conductive surface layer of the flexible board30.

The flexible board connector 1 comprises one or more fixing elements 20and a frame element 25. The fixing elements 20 are designed to couplethe flexible board connector 1 to the circuit board 40 and are furtherdesigned to carry the frame element 25 of the flexible board connector1. For instance, the fixing elements 20 may be mechanically mounted,soldered, or glued/adhered to the circuit board 40. For instance, amechanical mounting may be obtained by riveting, clamping or screwingthe fixing element through passages provided in the circuit board 40.Further, the fixing elements 20 may be solder tails for being solderedto the circuit board 40.

According to exemplary embodiments of the present invention, the fixingelements 20 may be provided integral with the frame element 25, thefixing elements 20 and the frame elements 25 may be formed as one piecefrom the same material, or the frame element 25 and fixing elements 20may be separate elements. Furthermore, the frame element 25 maymechanically engage the fixing elements 20. In particular, the fameelement 25 may be firmly or detachably coupled to the fixing elements20.Such mechanical engagement may be obtained by clamping or snappingthe frame element 25 to the fixing elements 20 such that the frameelement is mechanically firmly coupled by the fixing elements 25 to thecircuit board 40.

The flexible board connector 1 is designed to accept the flexible board30, which is for instance inserted, moved or slit into the flexibleboard connector 1 through an insertion opening in the frame element 25.The size of the insertion opening is adapted to accept the flexibleboard 30. During insertion the flexible board 30 may be inserted by amovement substantially parallel to the surface of the circuit board 40facing the flexible board 30.

FIG. 3 illustrates further schematic plan and side views of the flexibleboard connector according to an exemplary embodiment of the presentinvention. The centrally depicted illustration shows a schematic planview of the flexible board connector 1 according to an exemplaryembodiment of the present invention. Further schematic side views aredepicted, which represent side plan views along the cross sections A-A′,B-B′, C-C′ and D-D′. Each of the side plan views A-A′ and B-B′illustrating a cross section in short-side direction of the flexibleboard connector 1 shows two fixing elements 20 and the frame element 25at least mechanically engaged therewith.

The front plan view C-C′ illustrating a cross section in long-sidedirection of the flexible board connector 1 shows the insertion opening21 in the frame element 25, through which the flexible board 30 isinserted into the flexible board connector 1 and through which theflexible board 30 extends. The front portion of the frame element 25 isfor example further provided with a projecting element 26, which can beused as a locking element in cooperation with a cover element forming apressure piece. Such a cover element, which holds or retains an insertedflexible board within the flexible board connector 1 by exerting anormal force or pressure onto the inserted flexible board 30, will bedescribed below in more detail. According to embodiments of the presentinvention, the cover element is pivotably mounted to the flexible boardconnector 1. The pivot mechanism enabling the pivoting movement of thecover element may be realized by one or more hinge elements 27 shown inthe back plan view D-D′ in long-side direction of the flexible boardconnector 1. The pivot mechanism allows for pivotably mounting the coverelement to the frame element 25.

FIG. 4 is a perspective view showing a flexible board connector 1 of anexemplary embodiment of the present invention. The flexible boardconnector 1 holds or retains a flexible board 30 to a circuit board 40and electrically connects the wiring of the flexible board 30 to thecircuit of the circuit board 40.

The flexible board connector 1 comprises a plurality of conductivecontacts 45 for electrically connecting the circuit of the circuit board40 to the wiring of the flexible board 30. The flexible board 30 has acorresponding plurality of conductive contacts 35. Each conductivecontact 35 of the flexible board 30 is arranged to face a respectiveconductive contact 45 of the circuit board 40.

The conductive contacts 45 are embodied as conductive pads, each havinga substantially rectangular plan view and each having a substantiallyplanar conductive surface arranged for fitting against respectivecontacts 35 of the flexible board 30, which are also embodied asconductive substantially rectangular pads each having a substantiallyplanar conductive surface. The plurality of contacts 45 may be arrangedin the lengthwise direction of the flexible board connector 1 and extendmutually parallel in the short-side direction of the flexible boardconnector 1 as show in FIG. 4 for the same of illustration.

The plurality of contacts 45 of the circuit board 40 may be arranged inany other 1-dimensional or 2-dimensional pattern. The plurality ofcontacts 35 of the flexible board 30 should be arranged in asubstantially pattern, which matches the pattern of the plurality ofcontacts 45 of the circuit board 40

The flexible board connector 1 comprises fixing elements 20 such assoldering tails, a frame element 25 provided with an insertion opening21, and a cover element 70, which acts as force exerting component. Thefixing elements 20 may be arranged at the short sides of the frameelement 25 of the flexible board connector 1 and more particularly, eachshort side of the frame element 25 has arranged two fixing elements 20for the sake of example. The arrangement of the one or more fixingelements 20 should not be understood as limited thereto. This is, theone or more fixing elements 20 may be arranged at any one or more sidesof the frame element 25 including in particular the back side thereof(opposite to the side, at which the insertion opening is arranged). Thefixing elements 20 are in mechanical engagement with the frame element25 such that frame element 20 is substantially firmly mounted at thecircuit board. The mechanical engagement should be understood tocomprise a frame element 25 formed of one piece including integrally theone or more fixing elements 20.

The cover element 70 is pivotably attached to the frame element 25 atthe long back side thereof opposite to the long side having theinsertion opening 21. In a first opened position, the cover element 70extends from the frame element 25. By pivoting actuation the coverelement 70 is pivoted about an axis defined by one or more hingeelements arranged at the long back side of the frame element 25 andextending in direction of the long side of the frame element 25. In aclosed position the cover element 70 substantially flushes with theframe element 25.

In opened position, the flexible board 30 can be inserted into orremoved from the flexible board connector 1 through the insertionopening 21. In closed position, the flexible board 30 inserted in theflexible board connector 1 is retained against removal from the flexibleboard connector 1. The cover element 70 exerts a normal force onto theinserted flexible board 30. The holding mechanism will be described inmore detail with reference to the following figures.

The frame element 25 is further provided with a locking element 26,which can engage with the cover element 70 in closed position. Thelocking element 76 is designed as an opening, recess or aperture, whichengages with the counterpart locking element 26 designed as a projectionfitting into the opening. The opening is arranged at a handle of thecover element 70. By exerting a deforming force onto the handle or theframe element 25 nearby the projection, the engagement of the openingand the projection can be released.

FIGS. 5 a and 5 b illustrate schematic views of the flexible boardconnector 1 embodied above with reference to FIG. 4. For the sake ofschematic illustrating a cross sections in short-side direction aredepicted in FIGS. 5 a and 5 b. A side view of the frame element 25 withlocking element 26 is schematically depicted by dotted outlines. Thecover element 70 is pivotably mounted at the frame element 25. The oneor more hinge elements 27 and the pivoting axis, which extends in thisside view perpendicular to the view drawing plane, is schematicallydepicted as a circle.

In FIG. 5 a, the cover element 70 is in opened position. The flexibleboard 30 with the plurality of conductive contacts 35 may be insertedinto or removed from the flexible board connector through the insertionopening 21. The inserting or removing direction 81 is substantiallyparallel to the surface of the circuit board 40.

The cover element 70 has a substantially U-shaped structure including afirst leg 71 and a second leg 72. The end portion of the first leg 71 iscoupled to the one or more hinge elements 27. In addition, the handle ofthe cover element 70 with opening 76 is depicted. The U-shaped structurehas an opening width a, when the cover element 70 is in opened position.The opening of the U-shaped cover element 70 faces into the direction ofthe pivoting mechanism, which is herein exemplarily embodied by the oneor more hinge elements 27.

As aforementioned, the cover element 70 can be moved into closedposition by pivoting 80 about the hinge axis defined by the one or morehinge elements 27. The cover element 70 in closed position isschematically illustrated in FIG. 5 b. The cover element 70substantially flushes with the frame element 25. The projection 26engages the counterpart opening 76 such that the cover element is lockedin closed position. Before closure of the cover element 25, the flexibleboard 30 has been inserted through the insertion opening 21 of the frameelement 25 and brought into position such that the plurality ofconductive contacts 45 of the circuit board 40 and the conductivecontacts 35 of the flexible board 30 are in confronting and conformingarrangement. This means that the planar conductive surfaces of thecontacts 45 of the circuit board 40 and planar conductive surfaces ofthe contacts 35 of the flexible board 30 face each other and are inplanar close contact with each other.

During pivoting actuation of the cover element 70 into closed position,the free leg 72 of the substantially U-shaped cover element 70 gets intoplanar contact with the back surface of the flexible board 30, which isthe opposed surface to the surface being provided with the conductivecontacts 35. When the free leg 72 coming into direct contact with theflexible board 30, the free leg 72 is deformed in the direction of theleg 71 coupled to the pivot mechanism. The opening width a between thelegs in opened position of the cover element 70 is reduced to an openingwidth a′ between the legs in closed position. The deformation in theopening width of the U-shaped cover element results in a reactive,restoring force, which is exerted onto the flexible board 30 being incontact with the free leg 72 in closed position. The U-shaped coverelement 70 may be designed such that the deformed free leg is in closedposition substantially parallel to the back surface of the flexibleboard 30. Hence, a substantially uniform and normal force is exerted bythe deformed free leg 72 onto the back surface of the flexible board,which results in a substantially uniform pressure exerted by the contactsurfaces of the conductive contacts 35 of the flexible board 30 onto thecontact surfaces of the conductive contacts 45 of the circuit board 40.The normal pressure ensures a reliable electrical connectivity betweeneach adjoining pair of conductive contacts 45 and conductive contacts35. Further, the normal pressure ensures a retaining of the flexibleboard 30 inserted in the flexible board connector 1 against extractionor removing forces.

It should be noted that the design of a cover element 70 havingsubstantially the aforementioned U-shape may be subjected to materialand geometry restrictions. For instance, the size of free leg may havesuch an extent that a substantially uniform and normal force exerted bythe deformed free leg 72 onto the back surface of the flexible boardcannot be ensured. Although, the deformed free leg may be substantiallyparallel to the back surface in closed position, the force exerted bythe deformed free leg thereon may be non-uniform. Only within an area ofsmall size may be in closed linkage with the back surface of theflexible board. In this case, a bead element may be used, which acceptsthe force exerted by the cover element onto any area of the beadelement. The bead element transfers the force exerted thereon onto theback surface of the flexible board. The properties of the bead elementare selected such that the force exerted thereon is uniformed and theforce transferred by the bead element onto the back surface of theflexible board is exerted by a uniformed pressure substantially uniformover the area of contact between bead element and back surface of theflexible board. The use of a bead element may also reduce the risk thatforce exerted by the cover element causes distortion/deformation of allother elements including in particular the boards such that electriccontact between the conductive contacts may be at least degraded orlost. The bead element should have suitable material propertiesincluding for instance substantially rigid and/or buckling resistantproperties, which can ba obtained by adequate material selection and/orshape design of the bead element. The use of a bead element isillustratively explained with reference to the FIG. 6. However, such abead element may be also used in the exemplary embodiment of FIG. 4,whereas the exemplary embodiment of FIG. 6 may also be implementedwithout bead element.

The normal force or pressure, which is exerted by the conductivecontacts of the flexible board 30 onto the conductive contacts of thecircuit board 40, can be adapted by selection of material, of which thecover element 70 is made, and the geometry of the legs 71 and 72 of thecover element. A more stiff material, of which the legs of the coverelement 70 are made, results in a higher force exerted onto the flexibleboard 30 and hence pressure exerted by the conductive contacts 35 of theflexible board 30 onto the conductive contacts 45 of the circuit board40. The cover element 70 may be made of metal or any other deformationresistant material including in particular polymeric materials.

Because the conductive contacts of the circuit hoard 40 and the flexibleboard 30 are realized by contact pads, which are directly and firmlyprovided on the respectively boards, fine pitches of the contact padsfor instance in the range of 0.3 mm to 0.2 mm or below can be realized.Typical contact springs as known in the art are not required forrealizing the electrical connection between circuit board and flexibleboard. The requirement of contact spring limits significantly aneconomic downsizing of the pitch.

The frame element 25, which forms the housing of the flexible boardconnector 1, may be made of any material including polymeric materialsand metals. A metallic frame element 25 of the flexible board connector1 may provide an effective shielding of undesired electromagneticradiation.

FIG. 6 is a perspective view showing another flexible board connector 1of an exemplary embodiment of the present invention. Again, the flexibleboard connector 1 holds or fixes a flexible board 30 to a circuit board40 and electrically connects the wiring of the flexible board 30 to thecircuit of the circuit board 40.

The flexible board connector 1 comprises a plurality of conductivecontacts 45 for electrically connecting the circuit of the circuit board40 to the wiring of the flexible board 30. The flexible board 30 has acorresponding plurality of conductive contacts 35. Each conductivecontact 35 of the flexible board 30 is arranged to face a respectiveconductive contact 45 of the circuit board 40.

The conductive contacts 45 are embodied as conductive pads, each havinga substantially rectangular plan view and each having a substantiallyplanar conductive surface arranged for fitting against respectivecontacts 35 of the flexible board 35, which are also embodied asconductive substantially rectangular pads each having a substantiallyplanar conductive surface. The plurality of contacts 45 are arranged inthe lengthwise direction of the flexible board connector 1 and extendmutually parallel in the short-side direction of the flexible boardconnector 1.

The flexible board connector 1 comprises also fixing elements 20 such assoldering tails, a frame element 25 provided with an insertion opening21, and a cover element 70, which acts as force exerting component. Thefixing elements 20 are arranged at the short sides of the frame element25 of the flexible board connector 1. Herein, each short side of theframe element 25 has arranged two fixing elements 20. The fixingelements 20 are in mechanical engagement with the frame element 25 suchthat frame element 20 is substantially firmly mounted at the circuitboard. The cover element 70 is pivotably attached to the frame element25 at the long back side thereof opposite to the long side having theinsertion opening 21. In a first opened position, the cover element 70extends from the frame element 25. By pivoting actuation the coverelement 70 is pivoted about an axis defined by one or more hingeelements (not shown) arranged at the long back side of the frame element25 and in direction of the long side of the frame element 25 such thatin a closed position the cover element 70 substantially flushes with theframe element 25.

In opened position, the flexible board 30 can be inserted into or pulledout from the flexible board connector 1 through the insertion opening21. In closed position, the flexible board 30 inserted in the flexibleboard connector 1 is retained against removal therefrom. The coverelement 70 exerts a normal force onto the inserted flexible board 30.The holding mechanism will be described in more detail with reference tothe following figures.

The frame element 25 is provided with a locking mechanism 26, which canbe used to block the pivoting movement of the cover element 70 in closedposition. The lock mechanism 26 in engagement with the cover element 70firmly holds the cover element 70 in the closed position.

Additionally, a bead element 50 is arranged between the cover element 70in closed position and the flexible board 30 inserted into the flexibleboard connector 1. The bead element 50 is provided to accept thepressing force exerted by the cover element 70 in closed position ontothe bead element 50. The substantially planar bead element 50 ensuresthat the pressing force is substantially uniformly distributed among theconductive contacts 35 of the flexible board 30 such that asubstantially uniform pressure is exerted by the conductive contacts 35of the flexible board 30 onto the conductive contacts 45 of the circuitboard 40.

FIGS. 7 a and 7 b illustrate schematic views of the flexible boardconnector 1 embodied above with reference to FIG. 6. For the sake ofschematic illustrating a cross sections in short-side direction aredepicted in FIGS. 7 a and 7 b. A side view of the frame element 25 withlocking element 26 is schematically depicted by dotted outlines. Thecover element 70 is pivotably mounted at the frame element 25. The oneor more hinge elements 27 and the pivoting axis, which extends in thisside view perpendicular to the view drawing plane, is schematicallydepicted as a circle.

In FIG. 7 a, the cover element 70 is in opened position. The flexibleboard 30 with the plurality of conductive contacts 35 may be insertedinto or removed from the flexible board connector 1 through theinsertion opening 21. The inserting or removing direction 81 issubstantially parallel to the surface of the circuit board 40.

The cover element 70 has a substantially U-shaped structure including afirst leg 71 and a second leg 72. The end portion of the first leg 71 iscoupled to the one or more hinge elements 27. The U-shaped structure hasan opening width a, when the cover element 70 is in opened position. Theopening of the U-shaped cover element 70 faces into the direction of theinsertion opening 21, when the cover element 70 is in closed position.

As aforementioned, the cover element 70 can be moved into closedposition by pivoting 80 about the hinge axis defined by the one or morehinge elements 27. The cover element 70 in closed position isschematically illustrated in FIG. 7 b. The cover element 70substantially flushes with the frame element 25. The projection 26 canengaged with the first leg 71 such that the cover element can locked inclosed position and prevented by the projection 26 from pivoting intoopened position. The projection 26 may be moved into locking position bymovement in a direction parallel to direction, in which the first leg 71extends, when in closed position. Before closure of the cover element70, the flexible board 30 has been inserted through the insertionopening 21 of the frame element 25 and brought into position such thatthe plurality of conductive contacts 45 of the circuit board 40 and theconductive contacts 35 of the flexible board 30 are in confronting andconforming arrangement. Herein the insertion opening 21 is defined bythe bead element 50 having an inclined portion in the direction of theinsertion opening 21. The planar conductive surfaces of the contacts 45of the circuit board 40 and planar conductive surfaces of the contacts35 of the flexible board 30 face each other and are in planar closecontact with each other.

During pivoting actuation of the cover element 70 into closed position,the free leg 72 of the substantially U-shaped cover element 70 gets intocontact with the bead element 50, which in turn is forced intosubstantially planar contact with the back surface of the flexible board30, which is the opposed surface to the surface having attached theconductive contacts 35. The bead element 50 arranged movably or slidablyin normal direction, i.e. in the direction substantially perpendicularto the surface of the flexible board 30. Upon the free leg 72 cominginto direct contact with the bead element 50, the free leg 72 isdeformed in the direction of the leg 71 coupled to the pivot mechanism.The opening width a between the legs in opened position of the coverelement 70 is reduced to an opening width a′ between the legs in closedposition. The deformation in the opening width of the U-shaped coverelement results in a reacting or restoring force, which is exerted ontothe bead element 50, which substantially uniformly passes on the exertedforce onto the flexible board 30 being in substantially planar contactwith the bead element 50 in closed position. The slidable or movablearrangement of the bead element 50 allows for substantially informingthe force with respect to the surface area of the bead element 50. Thismeans a force which is exerted for instance punctually or linearly ontothe bead element 50 is accepted thereby and exerted over the overallsurface area to the flexible board 30 arranged below.

The U-shaped cover element 70 is designed such that the deformed freeleg is in closed position to the bead element 50. Hence, a substantiallynormal force is exerted by the deformed free leg 72 onto the beadelement 50, which normal force is uniformed by the bead element 50,which has freedom to slide in a direction substantially perpendicular tothe contact surface of the flexible board 30. The normal uniformed forceis passed onto the flexible board 30, which results in a substantiallyuniform pressure exerted by the contact surfaces of the conductivecontacts 35 of the flexible board 30 onto the contact surfaces of theconductive contacts 45 of the circuit board 40. The normal pressureensures a reliable electrical connectivity between each adjoining pairof conductive contacts 45 and 35. Further, the normal pressure ensures aretaining of the flexible board against removal forces within theflexible board connector 1.

The normal force or pressure, which is exerted by the conductivecontacts 35 of the flexible board 30 onto the conductive contacts 45 ofthe circuit board 40, can be adapted by selection of the material thecover element 70 and the geometry of the cover element 70. A more stiffmaterial, of which the legs of the cover element 70 are made, results ina higher force exerted onto the flexible board 30 and hence pressureexerted by the conductive contacts 35 of the flexible board 30 onto theconductive contacts 45 of the circuit board 40. The cover element 70 maybe made of metal or any other deformation resistant material includingin particular polymeric materials.

In general it should be noted that the deformation should be within themaximal limits of deformation acceptable by the selected material of thecover element 70. Exceeding the maximum limits of deformation may resultin a weakening of the cover element 70 for instance due to micro cracksand fatigue of material or even in a fracture of the cover element 70.

It should be also noted that the suggested flexible board connector 1having a resilient element provided to exert a pressure force pressingthe conductive contacts of the flexible board and the conductivecontacts of the circuit board such that the electrical connectivitybetween the adjoining contacts is ensured and retaining of the flexibleboard from the flexible board connector is prevented. The resilientelement and in particular the cover elements embodied above can bedesigned such that the flexible board connector accepts flexible boardswith a wide range of thinness of flexible boards.

As shown in FIG. 8, the flexible board 30 according to an exemplaryembodiment of the present invention has an end shape such that it ispartially cut away from the center in the widthwise direction. Both ofthe two flexible boards 30.1 and 30.2 have the substantially sameoverall shape. As shown in FIG. 8, the end portion of the flexible board30.1 located on one side of the flexible board connector 1 is insertedinto the flexible board connector 2 through an insertion opening in theframe element at the corresponding side thereof. Moreover, the endportion of the flexible board 30.2 located the other opposite side ofthe flexible board connector 1 is inserted into the flexible boardconnector 1 through an insertion opening in the frame element at thecorresponding side thereof.

From the forgoing description, it will be apparent that modificationscan be made to the system without departing from the teaching of thepresent invention. Accordingly, the scope of the invention is only to belimited as necessarily by the accompanying claims.

1-34. (canceled)
 35. An apparatus comprising: a flexible boardconnector, said flexible board connector comprising: a frame elementconfigured for being mounted with a circuit board, said frame elementhaving an insertion opening configured for accepting a flexible board,said flexible board having at least one conductive contact on a firstside of said flexible board; and a cover element having at least an openand closed position, said cover element in said closed positionconfigured to exert pressure against a second side of said flexibleboard when said flexible board is inserted into said frame element. 36.An apparatus according to claim 35, wherein the cover element isconfigured to retain the at least one conductive contact on saidflexible board in contact with at least one conductive contact on saidcircuit board when said cover element is in said closed position.
 37. Anapparatus according to claim 35, wherein the cover element is configuredto exert a force onto said flexible board when said cover element is insaid closed position.
 38. An apparatus according to claim 35, whereinsaid cover element is pivotably attached to said frame element and saidcover element is pivotable into said closed position, in which saidflexible board is retained in said flexible board connector.
 39. Anapparatus according to claim 35, further comprising a resilient elementwherein said pressure is exerted onto said second surface of saidflexible board when said resilient element is deformed.
 40. An apparatusaccording to claim 35, further comprising a bead element configured toreceive said pressure and to exert pressure onto said second surface ofsaid flexible board.
 41. An apparatus according to claim 35, whereinsaid cover element has at least a deformable portion, which whendeformed causes a restoring force effecting said pressure exerted ontosaid second surface of said flexible board.
 42. An apparatus accordingto claim 35, wherein said cover element has a portion beingsubstantially U-shaped and at least one deformable leg, which whendeformed causes a restoring force effecting said pressure exerted ontosaid second surface of said flexible board.
 43. An apparatus accordingto claim 35, wherein said cover element substantially flushes with saidframe element when in closed position.
 44. An apparatus, comprising: atleast one circuit board having at least one conductive contact; at leastone flexible board having at least one conductive contact on a firstside of said flexible board; and a flexible board connector comprising:a frame element configured for being mounted to said circuit board, saidframe element having an insertion opening for accepting said flexibleboard; and a cover element having at least an open and closed position,said cover element configured to exert pressure against a second side ofsaid flexible board when said flexible board is inserted into said frameelement when said cover element is in said closed position.
 45. Anapparatus according to claim 44, wherein said at least one conductivecontact on said flexible board is arranged against at least oneconductive contact on said circuit board when said cover element is insaid closed position.
 46. An apparatus according to claim 44, whereinsaid at least one conductive contact of said circuit board and said atleast one conductive contact of said flexible board have substantiallycongruent conductive surfaces.
 47. An apparatus according to claim 44,wherein said pressure is caused by a force exerted onto said flexibleboard having at least a normal force component relative to said secondsurface.
 48. An apparatus according to claim 44, wherein said coverelement is pivotably attached to said frame element, wherein said coverelement is pivotable into said closed position, in which said flexibleboard is retained in said flexible board connector when said coverelement is in said closed position.
 49. An apparatus according to claim44, further comprising a resilient element, wherein said pressure isexerted onto said second surface of said flexible board when saidresilient element is deformed.
 50. An apparatus according to claim 44,further comprising a bead element configured for accepting said pressureand exerting a uniformed pressure onto said second surface of saidflexible board.
 51. An apparatus according to claim 44, wherein saidcover element has at least a deformable portion, which when deformedcauses a restoring force effecting said pressure exerted onto saidsecond surface of said flexible board.
 52. An apparatus according toclaim 44, wherein said cover element has a portion being substantiallyU-shaped and at least one deformable leg, which when deformed causes arestoring force effecting said pressure exerted onto said second surfaceof said flexible board.
 53. An apparatus according to claim 44, furthercomprising a locking element configured for releasably locking saidcover element in said closed position when said locking element is inengagement with said cover element.